package com.hulden.rpc.common.util;

import com.dyuproject.protostuff.LinkedBuffer;
import com.dyuproject.protostuff.ProtostuffIOUtil;
import com.dyuproject.protostuff.Schema;
import com.dyuproject.protostuff.runtime.RuntimeSchema;
import org.objenesis.Objenesis;
import org.objenesis.ObjenesisStd;


import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

/**
 * 序列化工具类（基于 Protostuff 实现）
 *
 * @author hugo
 * @since 1.0.0
 */
public class SerializationUtil {
    private static Map<Class<?>,Schema<?>> cachedSchema = new ConcurrentHashMap<>();

    private static Objenesis objenesis = new ObjenesisStd(true);

    public SerializationUtil() {
    }

    /**
     * 序列化 (对象 -> 字节数组)
     * @param obj
     * @param <T>
     * @return
     */
    @SuppressWarnings("unchecked")
    public static <T> byte[] serialize(T obj){
        Class<T> cls = (Class<T>) obj.getClass();
        LinkedBuffer buffer = LinkedBuffer.allocate(LinkedBuffer.DEFAULT_BUFFER_SIZE);
        try{
            Schema<T> schema = getSchema(cls);
            return ProtostuffIOUtil.toByteArray(obj,schema,buffer);
        }
        catch (Exception e){
            throw new IllegalStateException(e.getMessage(),e);
        }
        finally {
            buffer.clear();
        }
    }

    /**
     * 反序列化（字节数组 -> 对象）
     * @param data
     * @param cls
     * @param <T>
     * @return
     */
    public static <T> T deserialize(byte[] data,Class<T> cls){
        try {
            T message = objenesis.newInstance(cls);
            Schema<T> schema = getSchema(cls);
            ProtostuffIOUtil.mergeFrom(data, message, schema);
            return message;
        }
        catch (Exception e){
            throw new IllegalStateException(e.getMessage(),e);
        }
    }

    @SuppressWarnings("unchecked")
    private static <T> Schema<T> getSchema(Class<T> cls){
        Schema<T> schema = (Schema<T>) cachedSchema.get(cls);
        if(schema == null){
            schema = RuntimeSchema.createFrom(cls);
            cachedSchema.put(cls,schema);
        }

        return schema;
    }
}
